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apply_along_axis

Apply a function to 1-D slices of an array along the given axis. The function is called once for each slice, and the results are assembled into an output array. Supports arrays of any dimensionality. For ND arrays, the function iterates over all combinations of indices on dimensions other than axis. 
function apply_along_axis(
  func1d: (arr: NDArray) => NDArray | number,
  axis: number,
  arr: ArrayLike
): NDArray
ParameterTypeDefaultDescription
func1d(arr: NDArray) => number | NDArray—Function that operates on a 1-D array and returns a scalar or 1-D array.
axisnumber—Axis along which to apply func1d.
arrArrayLike—Input array.
Returns: NDArray — The result of applying func1d along the specified axis. 
import { array, apply_along_axis, sort } from 'numpy-ts';

const a = array([[3, 1, 2], [6, 4, 5]]);

// Sort each row
const sorted = apply_along_axis(
  (row) => sort(row),
  1,
  a
);
// array([[1, 2, 3],
//        [4, 5, 6]])

// Sum each column (returns scalars)
const colSums = apply_along_axis(
  (col) => col.toArray().reduce((a, b) => a + b, 0),
  0,
  a
);
// array([9, 5, 7])

// Sum along axis 2 of a 3-D array
const b = np.ones([2, 3, 4]);
const result = apply_along_axis(
  (row) => row.sum(),
  2,
  b
);
console.log(result.shape);  // [2, 3]

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apply_over_axes

Apply a function repeatedly over multiple axes. After each application, the result is kept with the reduced axis preserved as a size-1 dimension, so subsequent axes remain valid. 
function apply_over_axes(
  func: (a: NDArray, axis: number) => NDArray,
  a: ArrayLike,
  axes: number[]
): NDArray
ParameterTypeDefaultDescription
func(a: NDArray, axis: number) => NDArray—Function that takes an array and an axis, returning an array with that axis reduced to size 1.
aArrayLike—Input array.
axesnumber[]—Axes over which to apply func, in order.
Returns: NDArray — The result of applying func over all specified axes. 
import { array, apply_over_axes, sum } from 'numpy-ts';

const a = array([[[1, 2], [3, 4]], [[5, 6], [7, 8]]]);
// shape: [2, 2, 2]

// Sum over axes 0 and 2
const result = apply_over_axes(
  (arr, axis) => sum(arr, axis, true),
  a,
  [0, 2]
);
// shape: [1, 2, 1]
// array([[[10], [22]]])

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shares_memory

Determine whether two arrays share the same underlying data buffer. Returns true only when the arrays definitely reference overlapping memory. 
function shares_memory(a: ArrayLike, b: ArrayLike): boolean
ParameterTypeDefaultDescription
aArrayLike—First input array.
bArrayLike—Second input array.
Returns: boolean — true if both arrays share memory. 
import { array, reshape, copy, shares_memory } from 'numpy-ts';

const a = array([1, 2, 3, 4]);
const b = reshape(a, [2, 2]);   // view
const c = copy(a);              // independent copy

shares_memory(a, b);  // true  -- b is a view of a
shares_memory(a, c);  // false -- c is a copy

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may_share_memory

Determine whether two arrays might share memory. This is a less strict check than shares_memory — it may return true even when the arrays do not actually overlap, but it never returns false when they do. 
function may_share_memory(a: ArrayLike, b: ArrayLike): boolean
ParameterTypeDefaultDescription
aArrayLike—First input array.
bArrayLike—Second input array.
Returns: boolean — true if the arrays might share memory. 
import { array, reshape, copy, may_share_memory } from 'numpy-ts';

const a = array([1, 2, 3, 4, 5, 6]);
const b = reshape(a, [2, 3]);

may_share_memory(a, b);  // true
may_share_memory(a, copy(a));  // false

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ndim

Return the number of dimensions of an array. 
function ndim(a: ArrayLike | number | bigint | boolean): number
ParameterTypeDefaultDescription
aArrayLike—Input array or array-like.
Returns: number — The number of dimensions (axes). 
import { array, ndim } from 'numpy-ts';

ndim(array([1, 2, 3]));             // 1
ndim(array([[1, 2], [3, 4]]));      // 2
ndim(array([[[1]]]));               // 3

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shape

Return the shape of an array as a number array. 
function shape(a: ArrayLike | number | bigint | boolean): number[] | readonly number[]
ParameterTypeDefaultDescription
aArrayLike—Input array or array-like.
Returns: number[] — The dimensions of the array. 
import { array, zeros, shape } from 'numpy-ts';

shape(array([1, 2, 3]));             // [3]
shape(array([[1, 2], [3, 4]]));      // [2, 2]
shape(zeros([3, 4, 5]));             // [3, 4, 5]

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size

Return the total number of elements in an array. 
function size(a: ArrayLike | number | bigint | boolean): number
ParameterTypeDefaultDescription
aArrayLike—Input array or array-like.
Returns: number — The total number of elements (product of shape dimensions). 
import { array, zeros, size } from 'numpy-ts';

size(array([1, 2, 3]));            // 3
size(array([[1, 2], [3, 4]]));     // 4
size(zeros([3, 4, 5]));            // 60

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geterr

Get the current error handling settings for floating-point operations. 
function geterr(): FloatErrorState
Returns: object — An object with keys divide, over, under, and invalid, each set to one of 'warn', 'raise', 'ignore', or 'print'. 
import { geterr } from 'numpy-ts';

const settings = geterr();
console.log(settings);
// { divide: 'warn', over: 'warn', under: 'ignore', invalid: 'warn' }

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seterr

Set how floating-point errors are handled. Returns the previous settings so you can restore them later. 
function seterr(
  all?: ErrorMode,
  divide?: ErrorMode,
  over?: ErrorMode,
  under?: ErrorMode,
  invalid?: ErrorMode
): FloatErrorState
ParameterTypeDefaultDescription
allErrorModeundefinedDefault mode applied to all error categories unless overridden by specific args.
divideErrorModeundefinedDivision-by-zero handling mode.
overErrorModeundefinedOverflow handling mode.
underErrorModeundefinedUnderflow handling mode.
invalidErrorModeundefinedInvalid operation handling mode.
Returns: FloatErrorState — The previous error handling settings. 
import { seterr, geterr } from 'numpy-ts';

// Suppress all warnings
const old = seterr(undefined, 'ignore', 'ignore');

// ... perform operations that may divide by zero ...

// Restore previous settings
seterr(undefined, old.divide, old.over, old.under, old.invalid);

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item

Get a single scalar element from an array. 
function item(a: ArrayLike, ...args: number[]): number | bigint | boolean | Complex

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tolist

Convert an array to nested JavaScript arrays (or a scalar for 0-D arrays). 
function tolist(a: ArrayLike): unknown

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tobytes

Return the raw bytes of an array in C-order by default. 
function tobytes(a: ArrayLike, order?: 'C' | 'F'): Uint8Array

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byteswap

Swap the byte order of each array element. 
function byteswap(a: ArrayLike, inplace?: boolean): NDArray

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view

Create a view of an array (same dtype view currently supported). 
function view(a: ArrayLike, dtype?: DType): NDArray

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tofile

Write an array to a file (Node.js-oriented API; see note in implementation for environment limits). 
function tofile(_a: ArrayLike, _file: string, _sep?: string, _format?: string): void

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fill

Fill an array in place with a scalar value. 
function fill(a: NDArray, value: number | bigint | boolean | Complex): void